Owner: unix - linux - storage URL:http://unixfoo.blogspot.com Join Date: Mon, 23 Jun 2008 02:05:00 -0500 Rating:0 Site Description: Unix Linux Storage , netapp, performance tuning, automation, hacks, tips, documents and useful hints Site statistics:Click here
NFS client : rsize wsize 2008-06-23 00:06:00 The nfs client mount command options "rsize" and "wsize" specify the size of the chunks of data that the client and server pass back and forth to each other. If no rsize and wsize options are specified, the default value is taken - which varies by which version of NFS and OS you are using. You will have to do some tests and find an rsize and wsize that works and is as fast as possible. You can tes
Linux : Forcing fsck on nxt boot 2008-06-20 06:44:00 If you want to force fsck on the next boot, just create a file called /forcefsck . If this file is present, then during next boot - the fsck is forced.# touch /forcefsckNow reboot the machine and when it comes up, fsck will be forced.# reboot
Read more:Linux
, Forcing
Encrypting a tar file using openssl 2008-06-20 04:04:00 In some cases, you may have to send your datacenter's passwd information to some of your collegues. Instead of sending them in plain text, you can use tar & openssl combination to encrypt that data. Here is how it can be done.Encryption :Tar & gzip the password file and encrypt using openssl des3 and a secret key. Replace the text "secretkey" with your secret password.[root@unixfoo-lin23 ~
Loadbalancer 2008-06-17 06:28:00 A good presentation from F5 explaining all features of Loadbalancer : -demo/
Download using wget 2008-06-16 23:07:00 You can use "wget" on Linux machine CLI to download files from http or ftp sites. Proxy configuration can be done for wget by exporting environment variablesInitialize proxy :# export http_proxy=unixfoo-proxy.unixfoo.net:80# export ftp_proxy=unixfoo-proxy.unixfoo.net:80Start download :Here im trying to download Fedora Core 9 image.# wget ftp://mirror.wbut.ac.in/pub/fedora/linux/releases/9/Fedora/i Read more:Download
Netapp : nfsstat command 2008-06-06 01:28:00 This command
displays the NFS and RPC statistics of filer. The command can be used to find the performance bottlenecks in NFS environment. This shows the metrics for each nfs call defined below. For more details refer . GETATTR: Get file attributesSETATTR: Set file attributesLOOKUP: Lookup filenameACCESS: Check access permissionREADLINK: Read from symbolic
How to resize Netapp Qtree Quotas .. ? 2008-05-28 01:01:00 1) Get the quotas file from netapp [root@unixfoo-l-adm root]# rsh unixfoo-nfs1 rdfile /etc/quotas > /tmp/quotas2) Edit the quotas file and change the quota for the required qtree. [root@unixfoo-l-adm root]# vi /tmp/quotas Example : Edit quotas as below /vol/vol1/qtree1 tree 250G #(Old entry) &n
Useful AIX tips 2008-05-08 09:18:00 Display paging space details# lsps -aPage Space Physical Volume Volume Group Size %Used Active Auto Typehd6 hdisk1 rootvg 8192MB &n Read more:Useful
Linux RPM database recovery 2008-05-07 06:29:00 Sometimes you may get the below error while running "rpm -qa" or any other rpm listing command. This error suggests that the RPM db is corrupted and you need to clean it up.rpmdb: PANIC: fatal region error detected; run recoveryerror: db4 error(-30977) from dbenv->open: DB_RUNRECOVERYHere are the steps to do it.Remove the rpm db lock information filesrm -f /var/lib/rpm/__db*Run the rpm rebuild Read more:Linux
Increasing swap performance 2008-05-06 03:46:00 If your Linux machine is configured with several swap partitions, the default trend is to use of one partition at a time. Once one swap partition has been full the next will be used. This is not always the best method for performance, since when a new process needs to be swapped to disk it may be forced to wait until another process is swapped out. For instance, if there are two swap partitions s Read more:Increasing
Netapp deduplication 2008-04-23 07:37:00 Netapp deduplication - is a new technology to control the rate of data growth. The average UNIX or Windows disk volume contains thousands or even millions of duplicate data objects. As data is created, distributed, backed up, and archived, duplicate data objects are stored unabated across all storage tiers. The end result is inefficient utilization of data storage resources. By eliminating redunda
HPUX tips 2008-04-22 06:14:00 1) Find number of processors in the machine.# /usr/sbin/ioscan -k -C processorH/W Path Class Description===============================160 processor Processor166 processor Processor#2) Find the model of the hardware# model9000/800/L2000-44#3) Find the network devices attached to the server# /usr/s
AIX performance monitoring : filemon 2008-04-11 10:29:00 "filemon" command monitors the performance of the file system, and reports the I/O activity. The I/O activity monitored is based on the time interval during which the filemon is run. It reports on various levels of file system utilization, including the LVM, virtual memory, and physical disk layers. Without any options, it runs in the background while application programs or system commands are be Read more:monitoring
HP-UX : Kernel Parameter Recommendations 2008-04-10 09:03:00 Below is the list of commonly recommended HPUX kernel parameters. But this may vary based on your application need.# Parameter
Value bufpages 0 # on HP-UX 10.X create_fastlinks 1 dbc_max_pct 25 fs_async 1 maxdsiz 2063806464 maxfiles 200 maxfiles_lim 2048 maxssiz (80*1024*1024) maxswapchunks 4096 maxtsiz (1024*1024*1024) ma
HPUX : Identify 32-bit or 64-bit kernel 2008-04-10 08:09:00 Here are the steps to identify whether you are running a 32-bit or 64-bit kernel
.getconf KERNEL_BITS will return whether it is a 32 bit or 64 bit. hpux1 # getconf KERNEL_BITS 32
Oracle's Direct NFS 2008-04-05 10:32:00 Direct NFS (DNFS) is an Oracle
Database 11g implementation of NFS client that runs as part of the Oracle Database 11g engine. Through this integration, the Oracle database engine optimizes the I/O access path to NFS server to provide improved scalability and reliability. In previous Oracle versions, the I/O operations to the NFS server were done through the native NFS client of the Operating syste Read more:Direct
Few /proc files 2008-04-04 11:21:00 /proc/cmdline - file has the parameters passed to the kernel while the system boots-up. /proc/kcore - This file represents the physical memory of the system and is stored in the core file format. The size of this file is equal to the size of the physical memory (RAM) used plus 4 KB./proc/files
ystems - This file displays a list of the file system types currently supported by the kernel. /
Know about Netapp Snapvault 2008-04-04 10:20:00 Netapp SnapVault is a heterogeneous disk-to-disk backup solution for Netapp filers and systems with other OS (Solaris, HP-UX, AIX, Windows, and Linux). In event of data loss or corruption on a filer, backed up data can be restored from the SnapVault secondary storage system with less downtime and less of the uncertainty associated with conventional tape backup and restore operations.About Snap
AIX : Managing service subsystem 2008-03-29 00:05:00 lssrv , stopsrc and startsrc are used to manage service subsystem in AIX. lssrc lists out all services that are active and inactive. "startsrc" and "stopsrc" are used to start and stop subsystems.# lssrc -aSubsystem Group PID Status
Netapp VIFs loadbalancing 2008-03-18 11:14:00 NetApp loadbalancing algorithm for determining ethernet load balancing (vifs) differs from Cisco, so it's normal to see unbalanced traffic in Netapp vifs. The Cisco method for determining load balancing is : The NetApp method is described as:((source_address XOR destination_address) % number_of_links) -- where source and destination take the last byte of the IP or MAC address to
Steps to create initrd 2008-03-06 11:31:00 Creating initrd using mkinitrd# mkinitrd -v -f --with=e1000 /tmp/initrd.gz 2.6.9-55Extracting the initrd image to add contents in it# mkdir /initrdroot# cd /initrdroot# gzip -dc /tmp/initrd.gz | cpio -id# ls /initrdrootbin dev etc init lib linuxrc lost+found mnt proc root sbin sys sysroot tmp usr Read more:create
Resizing ext3 filesystem 2008-03-03 05:27:00 The ext3 filesystem on Linux can be resized using ext2online . This can only be done when the filesystem is online (mounted) and where the the filesystem is on a resizable logical volume. More details at : I have'nt tried this program and there is no warranty for this program. Use it carefully.
Windows provisioning from PXE 2008-03-03 04:27:00 Two opensource solutions through which you can provision Windows
servers by network booting from a Linux PXE : ://unattended-gui.sourceforge.net/Good one & they worked for me.
NFS mount options 2008-02-21 03:23:00 Some important nfs mount
options in Linux. tcp - Specifies for the NFS mount to use the TCP protocol instead of UDP.rsize=8192 and wsize=8192 - These settings speed up NFS communication for reads (rsize) and writes (wsize) by setting a larger data block size, in bytes, to be transferred at one time. Do performance tests before changing these values.hard or soft - Specifies whether the program u
Linux : Virtual filesystem - Loopback device 2008-06-24 22:14:00 Sometimes you may need additional local partition or local mountable drives, but you dont have free blocks in the parition table. In that case virtual filesystem helps. You can create a virtual filesystem and mount them as a loopback device. Here are the steps to do it.Create a empty file with the mount of disk space you need. Here I have created a 1G file.[root@unixfoo23 ~]# dd if=/dev/zero of=/r Read more:Linux
Performance : Throughput analysis using iozone. 2008-09-05 04:51:00 The throughput of local filesystem or an nfs mount can be captured using iozone. The below command starts throughput calculation on /d1 filesystem , with 2 IO threads working on /d1/test/f1 and /d1/test/f2. You can increase the number of threads and filesize. This will be helpful in analyzing the IO rate on your system of nfs filesystem.For NFS, you can mount the filesystem with different "r Read more:Performance
Gnome 2.24 2008-09-26 21:17:00 GNOME 2.24 is released - the latest version of GNOME desktop. Gnome
focus is on ease of use, stability, and first class internationalisation and accessibility support. GNOME 2.24 includes all of the improvements made in GNOME 2.22 and earlier.Some interesting features includes .. "Empathy" instant messenger client Personal Time trackerEkiga conferencing clientEnhanced Google deskbarTabbed Fi
Xen management : virsh commands 2008-09-20 00:24:00 You can use virsh to manage xen virtual servers. Here are some basic commands using virsh.To list all the xen virtual machines configured on the dom0 server : [root@unixfoo-xen23 ~]# virsh list Id Name State---------------------------------- 0 Domain-0
Linux : Tunable TCP /proc parameters 2008-09-16 04:25:00 Tunable TCP settings can be found on /proc/sys/net/ipv4 . Here are the details of few of them.tcp_keepalive_probes : Number of KEEPALIVE probes tcp sends out, until the server decides that the connection is broken.tcp_keepalive_time : This value shows how often tcp sends out KEEPALIVE messages. The default is 7200 (2 hours).tcp_syn_retries : Number of times initial SYNs for a TCP connection attemp Read more:Linux
, parameters
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